Process of diffusion.



P. J. WOLFE. PROCESS OF DIFFUSION.

APPLICATION FILED DBO. 24, 1910.

1 ,0285650, Patented June 4;, 1912.

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vvvvvvvvvvv' PETER JACOB WOLFF, IBEDBURG, GERMANY.

PROCESS OF DIFFUSION.

Specification of Letters Patent.

Patented June 4, 1912.

Application filed December 24, 1910. Serial No. 599,146.

To all whom it may concern:

Be it known that I, PETER J ACOB WOLFF, a subject of the German Emperor,and resident of Bedburg, Germany, have invented a certain new and usefulProcess of Diffusion, of which the following is a specification.

Since the diffusion work has been introduced into the manufacture ofsugar, it has been repeatedly proposed and tried with a view ofextracting the juice by'dilfusion to .convey in a single diffusingapparatus beet-root chips and lixiviating liquid in a continuous mannerand in opposite direc tions. Until the present time, however, themethods proposed have not given satisfactory results. Previously whenchips were placed in the top of the diffusing apparatus and had todescend by gravity into the juice, it was found impossible to remove theexhausted chips in a suitable manner in addition to other diflicultieswhich rendered a regular diffusion impossible. Again when the chips wereconveyed in the opposite direction 2'. e. from below to the top,Archimedes screws, pistons and similar means were employed for forcingthe beet-root chips with the necessary pressure into the diffusingapparatus. The chips were in which case either so strongly compressedthat afterward they could notbe sufficiently loosened and distributed inthe diffusing apparatus or a part of them was ground and crushed, orboth, thus rendering the process impracticable. Likewise the stirringarms and screw blades, which were provided in the difiusing apparatusfor causing the chips to advance compressed the chips strongly on thefront surface while behind them the juice could pass freely withoutpassing through the tighter layers. It sometimes happened also thatchips remained stationary at some parts of the diffusing apparatus.

Now, the object of the present invention is to do away with thedrawbacks cited above. This object is attained in the first place byforcing the chips into the diffusing apparatus not as formerly in asolid form but mixed with diffusion juice as afluid mass while theexhausted chipsespeoially when the chips are conveyed from the top tothe bottomare flushed out of the diffusion apparatus by means of wateror are forced out of the apparatus mixed with lixiviating water as apulpy mass, the water after having been separated from the chips beingreturned to the diffusing apparatus. This method of working is new. Inthe process of diffusion as described in the French patent specificationNo. 401818, the ch1ps are it is true also mixed with hot juice but onlyin order to reheat them. Be-

chips before they are introduced into the diffusing apparatus with aview of rendering them soft and supple. In both cases the patentees hadonly the intention to introduce the chips in a solid form as is shown bythe fact that the devices employed by them are absolutely unsuitable forforcing liquid substances into the diffusing apparatus.

I In the drawings: Figure 1 is a diagrammatic section of an apparatusfor carrying out my improved method. Fig. 2 is a similar detail view ofanother form of structure for the bottom of the diffusing chamber. Fig.3 is a similar view of a still further form of chamber bottom. Fig. 4 isa similar view of another form of bottom.- Fig. 5 is a diagrammaticsection of a different form of apparatus for carrying out my improvedmethod.

The diffusing apparatus a comprises a vertical cylindrical vessel-whichis entirely open at its top' and has smooth inner surfaces. The funnelshaped sieve b has been mounted in the lower part of the vessel a. Thelatter is connected at its bottom end 0 by means of the pipe (Z (whichin the drawing is positioned behind the diffusing apparatus) with thepressure receptacle 6 and may be separated from the latter through themedium of the valve f. The fresh chips fall directly from the chippingmachine into the receptacle 6 and are mixed in the latter with such aquantity of juiceat thebeginning of the work with such a quantity ofwater-that a flowing mass is obtained. Or, the pulpy mass may be made upat any convenient place from chips and juice, and conveyed into thereceptacle 2 by means of a channel and a pipe, or other suitable When itis desired to start the diffusing apparatus, the pulpy mass of chips iscaused to flow from the pressure receptacle 6 into the cylinder (1. Whenthe latter is filled up to half its height, the lixiviating operation isbegun by withdrawing nice in a continuous manner at g and by causingwater to enter continuously at the top at h. (The sieve 7: and thetubular extension Z are not employed for this operation.) Now, as thechip pulp enters continuously at a, the chips rise in the diffusingapparatus higher and higher and are finally flushed out through theupper open end of the diffusion vessel a by means of water as exhaustedchips or are removed by any suitable mechanical device (scraper, drag,worm or the like). Before the water and the chips enter the diffusingapparatus, they are heated to suit the requirements.

The admission pipe may also pass through the center of the diffusingdevice. In this case it opens out at its bottom end above the sievechamber as shown by Fig. 2 of the drawing.

In diffusing apparatuses of sieve construction Z), Fig. 1 having largerdiameters it may happen that chips remain on the sieve permanently. Thismay be prevented by arranging the sieve of the diffusing apparatus notin the lower conical part of the latter but above it as for instance thesieve 7c in Fig. 1. The mixture of juice and chips is thus forced to bedistributed over the en tire cross section of the diffusing apparatusbefore it reaches the sieve and yields its juice.

In the form of embodiment as shown by Fig. 3 a flat iron wound in ahelicoidal manner and connected by means of horizontal arms wit-h avertical shaft, rotates in the sieve chamber and continuously scrapesthe chips from the sieve, causing them to rise.

A very good means for conveniently distributing and conveying the chipsis also afforded by the grate shown by Fig. I and which forms the upperlimit of the lower conical part of the difiusing apparatus. The combinedslots of this grate do not exceed in area that of the inlet pipe for thechip pulp. The chips are thus obliged,

when passing into the cylindrical part of the diffusing apparatus toutilize entirely all the slots of the grate and to push forward thecolumn of chips which is above them by exerting the same pressure at allplaces. In order to prevent the chips from remaining on the grate bars,the latter have such a shape, that their cross section forms anelongated vertical triangle.

Inthe' processes described heretofore the feed of the diffusingapparatus takes place without any interruption. It is however moreadvantageous not to introduce the chips in a continuous manner butregularly from time to time in larger quantities and to withdraw thejuice during the intervals between the different charges. In this case,the chips introduced last unite themselves each time after the chargingoperation is finished with the chips which were already in the diffusingapparatus and form a coherent, non-liqu1d mass, which at the nextcharging operation is pushed upward as a whole like a large plug.

In order to prevent during the intervals between the different feedingoperations, the chips from settling down too much in the piping throughwhich the mixture of chip and juice is introduced from below into theapparatus, a part of the fresh diffusion juice orif the piping has avery large diameter-the entire juice is conveyed through the said pipingfrom below to the top. The diffusion then already begins in the saidpiping, which thus becomes so to speak a diffusing apparatus.

(The chip pulp may also be stored up in a collector provided at thebottom of the diffusing apparatus and be forced from the said collectorinto the diffusing apparatus by means of compressed air or steam).

The method just described may be carried out in the simple device shownby Fig. 1 by causing the juice to escape tl'irough Z when the chips areintroduced, and through 9 at other times. The process may be carried outbetter by means of the diffusing apparatus shown by Fig. 5. In fact,this apparatus allows the lixiviation under high pressure as alreadymentioned and is also provided with a device for causing the chips toadvance regularly in the diffusing apparatus, this device being, it istrue not so simple as that described above but working with morereliability. This diffusing apparatus is provided at the top and at thebottom with two openings n, 0, p and g' which may be closed by means ofthrottle valves. Water coming from an elevated reservoir enters at n andthe exhausted chips are forced out through 0. The juice escapes at- 9and the chips are introduced into the apparatus through 9. At thebottom, the an nular sieve 1- forms together with the enlarged sievemouth the juice collecting chamber 8. Provided in the sieve chamber is agrating 25 made of round iron bar and framed in a fiat iron ring whichapplies itself to the sieve 1'. The grating is secured to the rod 1 andmay be raised and lowered shaft 00 and may at the same time be raisedand lowered. Fig. 5 shows the device in the position which it occupieswhen juice is drawn off. The water flows in at the top at n and escapesbelow at p as juice. The admission and escape openings for the chips areclosed. The grating 25 occupies its lowermost position. In the top partof the difi'using apparatus, the chips are loosened by the rake w andform with the water a fluid mass. When it is desired to introduce chipsinto the diffusing apparatus, the openings n and p are closed and those9 and 0 are opened. The pressure exerted by the entering chip pulpraises then the entire contents of the apparatus and the upper part ofsaid contents is forced out through 0. The grating t also rises as it ispressed from below against the rising column of chips. The latter isthus held together and the sieve r is cleaned at the same time. The rakew is also raised by the rising column of chips, but penetrates at thesame time deeper and deeper into it and loosens the upper layer of chipsfor the next following escape of chips. When the grating t has reachedthe upper edge of the sieve, it is rapidly pulled down again through thechip pulp until it reaches the lower edge of the sieve. During thismotion, a rotary mot-ion may be imparted to the grating so as tothoroughly clean it from the chips which might adhere thereto. Theopening 0 is then closed and p opened. The chip pulp which stillcontinues arriving through the grating 25, then forces the juice throughthe sieve out of the diffusing apparatus until finally the entire sievechamber is crammed with chips. If the passage 9 is then closed and thepassage 01. opened, the water entering the vessel under pressurepenetrates into the chips from the top toward the bottom as in anordinary diffusing apparatus and escapes at p as fresh difiusing juice.From 79 this fresh juice descends entirely or partly into the feed pipefor the chips, rises slowly in this feed pipe, preventing the settlingdown of the chips, and escapes through the sieve at z. The juice whichescapes through 10 during the feeding operation is directly carried offby the duct y. When the quantity of juice corresponding to the quantityof chips in troduced has been drawn off, the difl'using apparatusreceives a fresh charge and work is continued in the manner describedabove.

The stop devices for the chip pulp are provided with a securedperforated closing flap positioned in advance of the closing flapproper, the said perforated flap being closed first and thus allowingonly liquid to pass. This liquid washes the closing flap which may thenbe easily and tightly closed.

The process and the device according to the present invention maybeemployed, and

this is needless to say, for lixiviating other materials.

The extraction of juice according to the present invention has thefollowing advantages in comparison with the ordinary process ofdiffusion: 1.No waste water is produced. 2.-All the component parts ofthe beet-roots are extracted without any loss as juice and exhaustedchips. 3.The diffusing apparatus and the chip press may be connectedtogether in such a manner by means of pipes that the water used forcarrying the chips away and the water resulting from the pressingoperation are brought back into the diffusing apparatus without cominginto contact with the surrounding air. 4.Loss of juice produced by leakyvalves or wrongly adjusted valves, which often occur in ordinarydifl'usionwork, are entirely prevented. 5.The device and the process arevery simple and cheap. All that is necessary is to control the march ofthe work from time to time according to the results of the analysiso-fthe exhausted chips or press water.

Having now fully described my said invention, what I claim and desire tosecure by Letters Patent, is:

The process of extracting juice from beet chips by lixiviation in whichthe diffusion juice and the chips travel in opposite directions,consisting in making a fluid mixture of the chips and diffusion juice,forming a vertical column composed of such mixture, feeding water tothe. upper part of the column Withdrawing the extract of juice from thelower end of the column feeding fresh portions of the mixture of chipsand diffusion juice to the column from below and withdrawing theexhausted chips from the top of the column as they are forced upward bythe entering mixture.

In testimony whereof I have hereunto set my hand in presence of twowitnesses.

PETER JACOB WOLFF.

Witnesses:

LOUIS VANDORY, GERTRUD BONA.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

